The present invention relates to a refrigeration system suitable for use in the zero gravity conditions of outer space. More specifically, the present invention relates to a chemical refrigeration system in which a liquid is chilled from the endothermic reaction associated with dissolving selected chemicals in the liquid.
Conventional mechanical refrigeration systems, which operate on the principles of vapor compression and utilize conventional components such as mechanical compressors and condensers, will not work properly in the zero gravity conditions of outer space because vapor cannot be separated from liquid without a great deal of difficulty under these conditions. Accordingly, when it is desired to chill or refrigerate liquids in outer space, conventional vapor compression systems may not be utilized.
The present invention takes advantage of the fact that certain chemicals, when dissolved in a liquid such as water, produce an endothermic reaction. This endothermic reaction cools the liquid down below the ambient temperature. The degree of cooling depends on the nature of the chemical used. However, the amount of cooling is proportional to the amount of the chemical which may be dissolved in the associated liquid, which is fixed by the solubility limitations of the chemical. Therefore, for any given volume of liquid and associated chemical to be dissolved therein, there is a limit on the amount of cooling that can be achieved, namely, the drop in temperature of the resulting solution, as compared to the original temperature of the liquid. Therefore, if one wants to chill a liquid from, for example 82.degree. F. to 36.degree. F., such a drop in temperature is difficult to obtain merely by dissolving a quantity of a selected chemical in an associated liquid.
Accordingly, a need in the art exists for a refrigeration system which utilizes the principles of chemical refrigeration achieved by dissolving a selected chemical in water, but utilizes the chemical/liquid solution in a system in such a manner that larger temperature drops can be achieved than normally permitted by the solubility limitations of the chemicals utilized.